Thio-urea compound and process of making same.



UNITED STATES PATENT OFFICE.

ADOLF ISRAEL AND RICHARD KOTHE, OF ELBERFELD, GERMANY, ASSIGNORS TO THE FARBENFABRIKEN OF ELBERFELD COMPANY, OF NEW YORK.

THlO-UREA COMPOUND AND PROCESS OF MAKHTG SAME.

SPECIFICATION forming part of Letters Patent No. 653,678, dated July 1'7, 1900.

Application filed April 2, 1900. Serial No. 11,240. (No specimens.)

e/\Aa AA/ The new thio-urea derivative thus obtained maybe employed for the manufacture of valuable azo dyestuifs.

In carrying out our new process practically we can proceed as follows, (the parts being by weight:) To a solution of 23.9 parts of beta,- amido-alpha -naphthol-beta sulfonic acid in about from two hundred to three hundred parts of water, to which so much sodium carbonate has been added as to render it slightly alkaline, we add two hundred to three hundred parts of ethylic alcohol, from twenty to twenty-five parts of carbon bisulfid, and from 0.4 to 0.5 parts of powdered sulfur. The mixture thus obtained is boiled in a vessel provided with a reflux condenser until the evolution of sulfureted hydrogen ceases. After the alcohol and the superfluous carbon bisulfid have been distilled oi the reaction mix- I I 4 l l l lowing equation:

ture is filtered in order to remove the sulfur which has been precipitated. The filtrate is then acidulated by means of hydrochloric acid and the thio-urea derivative is precipitated from the acid solution by the addition of common salt. For further purification it is extracted with water, filtered, and then me cipitated again by the addition of common salt. The pure sodium salt of the new body thus ob tained crystallizes from water containing com= mon salt in the shape of White leaves, which are readily soluble in cold and very readily in hot water; and soluble with difficulty in alcohol. The barium salt represents white leaves, which are dii ficultly soluble in cold and readily soluble in hot water. The calcium 7o salt forms mother-of-pearl-like shiningleaves, which are very readily soluble in hot and less soluble in cold water. These salts are in what manner the same is to be performed,

what we claim as new, and desire to secure by Letters Patent, is-

1. The process for producing a new thiourea derivative of amidonaplithol sulfonic acid by first dissolving a mixture of beta,- amido-alpha naphthol bet-a sulfonic acid and sodium carbonate in water, secondly heating the solution thus obtained with caroon bisulfid, sulfur and' alcohol and finally isolating the resulting thio-urea derivative, substantially as hereinbefore described.

2. As a new article of 'inanufacture the thio-urea derivative of beta -ainido-alpha naphthol-beta sulfonic acid which in the form of the free acid has the following forniula:

I OH

and in the form of the sodium salt consists of white leaves being capable of combining with oneand likewise with two molecules of diazo compounds, being readily soluble in cold, very-readily soluble in hot water, and which on boiling with the twenty-fold quantity of hydrochloric acid of twenty per cent. dissolves and after some time beta -amidoalpha -naphthol-beta -sulfonic acid is regenerated and precipitates, substantially as hereinhefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ADOLF ISRAEL. RICHARD KOTHE. Witnesses:

OTTO Komc, HANS SCHADDY. 

